Cylinder Sleeve Research Articles

Dynamic Modeling and Simulation of a Discrete Incremental Hydraulic Positioning System Controlled by Binary Valves

This article presents the conceptual design, operation principle, dynamic modeling, and simulation results of a discrete incremental hydraulic positioning system (DIHPS) intended for use in high-precision, heavy-load industrial automation solutions. An original solution for precise incremental step positioning using DIHPS is proposed, comprising an n-step linear double-acting hydraulic actuator (HA) with a double rod, cylinder sleeve with outflow gaps, binary valves (BVs) bleed-off into the tank, and fixed throttle valves (TRVs) at the inlets of the actuator chambers. The discrete incremental shift of the HA is determined by controlling the opening and closing of the individual BVs, and the step shift of the HA piston stops at the opening location of the BV. A dynamic model of incremental step shift for DIHPS is developed, considering the behavior and relationships of its individual elements. A dynamic model of HA with and without a hydropneumatic accumulator (HPA) is presented. HPA has been shown to effectively dampen piston vibrations and pressure peaks at the HA stop position. The design assumptions, dynamic models, and discrete incremental positioning of the DIHPS are verified by simulation tests and assessed with quantitative indicators. Innovative DIHPSs have significant practical potential in the discrete incremental positioning of heavy loads.

Метод оценки факторов, влияющих на вибрацию судового дизеля, вызванную работой цилиндропоршневой группы

The efficiency of the use of the marine fleet is associated with a reduction in the cost of transportation, the need for which is steadily increasing. A significant share of the total transportation costs is occupied by the costs associated with the operation of ships, therefore, reducing these costs is a reserve for reducing the cost of maritime transportation. The problem of increasing the efficiency of the operation of marine vessels is closely related not only to reducing the cost of it, but also to reducing the time for maintenance and repair of ships. The existing system of scheduled preventive maintenance and repair provides for the maintenance and restoration of the normal technical condition of the vessel and its elements with a pre-planned frequency. The transfer of ships to work with extended repair periods is possible only when solving a whole range of engineering and technical measures and scientific research aimed at improving the quality of repairs, the level of technical operation, improving logistics, etc. An essential role in this is played by the use of modern methods and means to determine the technical condition of shipboard devices and mechanisms, primarily engines of shipboard power plants (SEUs), without disassembling them. High vibration loads of SEU parts lead to fatigue stresses, accelerate wear of the contacting surfaces, reducing the reliability and service life of marine diesel engines, therefore monitoring of their vibration activity is important, especially during operation. The safe operation of ships of the transport fleet largely depends on the reliability of marine diesel engines. Technical means of monitoring their operability in the process of work are currently insufficiently effective and need to be improved. It is relevant not only to develop new, more advanced and mobile hardware and software, but also to search for new scientific and methodological approaches to using the information contained in the spectrum of vibration parameters. Marine diesel internal combustion engines are complex systems that involve many variable parameters. The study of such engines requires the use of methods that can be used to systematically investigate the influence of various factors on their operation, in particular, random experimental schemes are used, since they provide systematic control over variable parameters and maximize the accuracy of estimates. The results of the application of the method of ranking the factors influencing the vibration of a marine diesel engine are presented in order to establish the most significant of them. A mathematical model is presented that allows calculating current values and predicting changes in the most significant indicators, among which the most important is the size of the gap between the piston and the cylinder sleeve.

Моделирование и оценка интенсивности старения моторного масла в судовых тронковых дизелях при их наддуве

A computational and experimental model of the aging of lubricating oil in different directions is presented, taking into account the influence on the intensity of its degradation of the degree of forcing (thermal load) and the technical condition of diesel, the quality (motor group) of the lubricant product and the sulfur content in the fuel. The novelty in assessing the aging of the lubricant in a tank diesel engine when forcing it by supercharging consists in the formation of a thermal load on the oil film, which determines the aging rate of the engine oil on the cylinder sleeve of the engine. It is reported how the density of the heat flux acting on the surface of the oil film swept by the piston is experimentally fixed and averaged over the height of the sleeve and the angle of rotation of the crankshaft during the engine operating cycle. The influence of the factors under consideration on the specific rate of aging of lubricating oil per unit area of the sleeve surface in contact with gases in the direction of additive activation, decrease in alkalinity, increase in acidity, tar formation and accumulation of insoluble products has been identified. The lines of equal values of the hypersurfaces of the response functions for the specific intensity of the alkalinity response and the formation of insoluble products of tar formation and acidity growth are illustrated. The requirements for engine oil have been formed according to the level of alloying with multifunctional additives, depending on the degree of boost (average effective pressure) of supercharged marine tank diesels. As a result of the analysis of the aging rate of engine oil in modern marine diesel engines with medium and high boost, the expediency of using unified type oils in them has been confirmed M-10(14)G2CS and M-14(16)DCL20 with multifunctional additives MASK and PMS for the combustion of distillate fuels and their mixtures with fuel oils with a sulfur content of up to 0.5%.

Повышение эффективности уплотнений деталей цилиндропоршневой группы судовых дизелей

During the engine operation, the piston rings wear out and the grooves under the piston rings are destroyed, as a result of which there is a decrease in the sealing of the combustion chamber. This problem has been usually solved by replacing the old, spent piston and rings with new ones. There is considered a method of extending the life of the cylinder piston group. The proposed method consists in changing the composition and design of the upper piston ring, which is primarily responsible for sealing the combustion chamber. It is proposed to bore the groove of the upper piston ring, until all defects obtained during the engine operation are eliminated; then, to make two piston rings fitting the size of the groove and install them into the bored groove. Installation of the rings should be done in such a way that the axial locks are positioned in line in the opposite direction. In this position of the rings, gases entering the joint of the upper ring rest against the solid body of the lower ring and the further path for them is terminated. The breakthrough of gases from the working plane into the crankcase is excluded, the indicator efficiency of the engine increases, the wear of the cylinder bushings of pistons and rings decreases, the vibration of the flutter type is eliminated. For installation, standard piston rings are used with a slight modification, which consists in adjusting the height and changing the profile of the rings in order to reduce wear of the cylinder sleeve and rings during operation. According to the test results, conclusions were drawn about the increased service life in the manufacture of the piston rings with optimal geometry and about a positive effect on the engine performance.

Technologies assuring the service properties of friction pairs with cellular microrelief surfaces

Article focuses on the improvement of the technologies used to improve the durability of friction pair components. The authors use the piston compressor to study cellular microrelief surfaces of cylindrical components. The cells are shaped as elliptic paraboloid with uneven positive parameters. The use of cellular microrelief surfaces is highly preferred as they reduce the attrition wear of the friction pairs through assuring the hydrodynamic load capacity of the lubrication layer with the shape of the microrelief. The research goals included the parametric analysis of the lubrication layer behavior in the gap between the microrelief cells. To do this, the authors developed an analytical model based on the theory of hydrodynamic lubrication and constructed a CFD model using the ANSYS Fluent software. To contain the transfer equations, the authors used the turbulence model SST k–ω. Both models showed that the maximum hydrodynamic load capacity coincided with the 75%-length of the major axis of the elliptic cell, which also corresponds to 0.128 mm in cell depth. The maximum lifting hydrodynamic pressure on one microrelief cell amounted to 3 kPa. Based on the results of the parametric analysis, the authors claim that the cellular microrelief can be efficiently used to assure the service properties of friction pairs in process units. Keywords: friction pair; cylinder sleeve; piston ring; cellular microrelief; hydrodynamic model; mathematical model; ANSYS Fluent; two-dimensional parametric analysis.

Effect of addition of MWCNTs to a mineral lubricant on Diesel engine performance

In this research, a diesel engine lubricant, modified with Multi-Walled Carbon Nanotubes (MWCNTs) was evaluated. Carboxylic group functionalized MWCNTs were dispersed in 15W40 mineral oil for Diesel engines and retaining ring and cylinder sleeve materials from F300 diesel engine were used for tribological tests. The Nanofluid (0.1 0.5 and 1% wt.) rheological behavior was characterized. Nanolubricants with 1% wt and base oil were evaluated on a Pin-on-Disk test. Results suggest both wear rate and coefficient of friction reduction when MWCNTs are used, while no significant rheological properties changes were observed.

Determining the probability of failure of marine diesel engine parts

Maritime transportation is the essence of the international economy. Today, about ninety percent of world trade is carried out by sea through 50,000 merchant ships. Most of these vessels are powered by mainline diesel engines due to their reliability and fuel efficiency. Reliability of system elements in general depends on random failures, significant wear during operation, additional wear during start-up. Accidental damage to diesel engine components is a major hazard during operation, as some parts (such as cylinder liners and pistons) are usually replaced during repairs. On the other hand, preventive service does not eliminate random malfunctions. Therefore, in the general problem of assessing the reliability of a diesel engine, there is a mathematical problem of assessing the reliability and durability, taking into account only the random failures of its elements, which are of the greatest practical importance. The purpose of the work is a mathematical study of the reliability of parts of the cylinder-piston group of the main engines of dry cargo ships. Using a systematic approach and a probabilistic statistical method, it was established that the most common and difficult case is the simultaneous action on a system element (for example, a cylinder sleeve) of factors that cause wear during the period of operation (including during the start-up period) and accidental failures. It was determined that the quality of the cylinder-piston system in ships of the "Ostriv Rosiyskiy" type is higher than in the ships of the "Simferopol" and "Murom" types. Empirical formulas for estimating the probability of emergency failure of main engine system elements during the period of operation between factory repairs were obtained, where the main danger during the period of operation was carried by accidental failures. Based on the results of the study, it is possible to establish a schedule for the periodicity of maintenance of the ship's main engine and the cost of losses due to ship downtime due to failures, and can also be used in the reliability study of other types of ship's main engines. The results make it possible to determine the reliability of the parts of the cylinder-piston group of the main engines of dry cargo ships. and, in particular, to establish the maintenance schedule of the ship's main engine and the cost of damages due to ship downtime due to failures, and can also be used in the study of the reliability of other types of main engines of other series of ships

Методика определения теплового состояния втулки цилиндра при центрoбежном индукционном напекании

The temperature distribution in the ship engine cylinder sleeve during its heating and cooling is one of the most important factors affecting formation of the structure and properties of coatings in the process of cylinder recovery by the method of induction centrifugal sintering. The article discusses experimental studies, which allow presenting graphs of the temperature distribution over the diameters of the ship engine cylinder sleeve during its heating and cooling. The thermophysical properties of the sleeve were found to significantly affect the process of sintering powder materials. By varying the heating rate, it is possible to obtain coatings at different temperatures and sintering time. Modeling the temperature distribution in the wall of the cylinder sleeve during centrifugal induction sintering depending on the sintering time is of interest as well as taking into account the geometrical parameters of the sleeve, heat transfer, thermal conductivity, sleeve material, ambient temperature, etc. Expressions are obtained for determining the temperature distribution in the wall of the cylinder sleeve during induction centrifugal sintering. Using the obtained formulas, it is possible to simulate and obtain in advance the temperature distribution in the wall of the cylinder sleeve by setting the values of the parameters of centrifugal induction sintering. Modeling in the Autodesk Fusion 360 the temperature distribution in the sleeve during induction heating was obtained as well as visual display of the change in the temperature field in the sleeve during induction heating.

THEORETICAL SUBSTANTIATION OF CAVITATION WEAR INTENSITY REDUCTION OF CYLINDER SLEEVE WALLS BY APPLICATION OF ANTI-CAVITATION COATING

One of the ways to increase service life of internal combustion engines is to reduce cavitation wear intensity of the outer wall of the cylinder sleeves. The most promising, at present, method is application of anti-cavitation coating on the outer surface of the cylinder sleeve. The aim of the research was to establish theoretical dependencies that allow to substantiate the properties and thickness of the anti-cavitation material applied to the outer wall of the cylinder sleeve. Theoretical studies of cavitation wear intensity along the destruction depth of the cylinder sleeve wall established that when choosing cavitation-resistant materials, it is necessary to have regard to material structure and give preference to those materials that are characterized by high resistance to microvolumes of plastic deformation under microshock action and are capable of withstanding operating modes over a wide temperature range. The materials of the polytetrafluoroethylene group - fluoroplasts - most fully meet these requirements. Studies of the fluoroplastic coating applied to the outer wall of the cylinder sleeve, using the obtained theoretical dependencies, showed that the minimum wear rate of the cylinder sleeve of 0.0006 mm3/cycle is achieved with a fluoroplastic coating thickness of the outer surface of the cylinder sleeve with a thickness of 1.8 mm. In this case, the difference in heating of a typical sleeve and a sleeve with a fluoroplastic coating with an increase of the heating temperature of the inner wall of the sleeve decreases from 15% at a temperature of 50 °C to 5.7% at a heating temperature of 150 °C, that is, the application of a fluoroplastic coating on the outer wall of the cylinder sleeve does not lead to a change in the heat stress of the cylinder sleeve and will not affect the heat balance of the internal combustion engine. Thus, the obtained theoretical dependences make it possible to establish and justify not only the properties of the anti-cavitation material, but also the thickness of its application to the outer surface of the cylinder sleeve.

Design features of the new generation engines of the A-41SI family

Design documentation on diesel engines of the A-41SI model is analysed. By results of the analysis it is revealed that on diesels of this type individual heads of cylinders, an electric starter with a pro-rate for start of engines are introduced, assembly units and details are improved: cranked shaft, sets of radical and shatunny inserts, cylinder sleeve, the piston, set of piston rings, casing with disks of the coupling of coupling, etc. Introduction of new constructive changes on A-41SI diesels allowed to raise their rabotosposbnost and durability.

Cylinder sleeve of the internal combustion engine. Mathematical model of the deformation process

During the operation of internal combustion engines, deformation of the cylinder sleeve is possible, which causes its premature wear during the operation of the “piston ring – sleeve” pair. Imagine the sleeve as a two-stage hollow cylinder with forces applied to it, which cause deflection in the section. It can be assumed that if the greatest deformation of the cylinder is in the section of the application of forces, then with distance from this place it will decrease. At some distance from the point of application of forces, the deflection of the sleeve will be equal to zero. It is required to simulate a mathematical formula that would make it possible to evaluate the possibility of estimating the value depending on the basic geometric dimensions of the cylinder sleeve. A mathematical model of the deformation process of a hollow two-stage sleeve of an internal combustion engine has been developed, an analytical dependence has been obtained for the value of the “neutral” section depending on the main geometrical dimensions of the cylinder sleeve of the engine, a rather extensive analysis of the influence of various parameters on the value of the “neutral” section has been carried out.

Assessment of the impact of the technical condition of the cylinder-piston group parts on nitrogen oxide emissions

Nowadays, a lot is paid to environmental protection issues, including those related to reducing emissions from ships of the sea and river fleet, which is reflected in many works. Constant control over the content of harmful emissions in the environment forces us to deal with the issues of reducing emissions from diesel engines at the design stages and during operation. The solution to this problem allows us to consider 2 directions: constructional and the use of special equipment for capture and neutralization. In the best case, a combined method can be used, i.e. constructional with the use of capturing equipment for harmful components in diesel exhaust gases. This paper presents an analysis of the influence of various factors that reduce the load on the atmospheric air from nitrogen oxides of marine diesel engines, namely, from the operating settings of the diesel engine and its wear. On the ships of the river fleet, diesel engines are used with various mixture formation with volumetric, volumetric-film, vortex mixture formation. The leader in the listed group is the volumetric mixture engines. The paper provides an assessment of the research carried out to analyze various methods of influencing the working process of a diesel engine - the type of mixture formation, wear of the cylinder sleeve in order to determine their influence on the formation of NOx emissions.

Analisa Kekerasan dan Keausan Cylinder Sleeve dari Besi Cor Kelabu FC250 Hasil Sand Mold Casting

<p><em>The Cylinder sleeve is an engine component that is mounted on the cylinder block which functions as a piston glide base. The cylinder sleeve is made of FC250 gray cast iron. FC250 is a gray cast iron that has lamellar graphite with a tensile strength of at least 250 MPa. This study aims to determine the mechanical properties of hardness and wear of the Cylinder Sleeve made of gray cast iron FC250. The method used in this research is gray cast iron which is cut with a length of 5.5cm, thickness 0.7cm, height 0.7cm which is formed according to the standard size of the hardness and wear test. The tests carried out include testing brinell hardness and wear. The results showed that the lowest hardness value was 134.63BHN and the highest hardness value was 191.43BHN. The increase in hardness values is influenced by the carbon content that cannot be spread evenly, which is followed by a fast cooling rate. The results of the wear test obtained the lowest price of 0.00017mm³/kg.m and the highest wear price of 0.00028 mm³/kg.m.</em></p><p><em><br /></em></p>

Developing technology of creating wear-resistant ceramic coating for internal combustion engine cylinder sleeve

This paper presents the results of testing a wear-resistant ceramic coating on the work surface of an internal combustion engine (ICE) cylinder’s sleeve. A combined coating formation technology is described that consists in applying an aluminum layer to the sleeve’s work face by gas dynamic spraying and then covering this face with a ceramic layer by microarc oxidation (MAO). A tenfold reduction in the reinforced sleeve has been determined by the accelerated comparative wear rig tests of reference (new) sleeve-piston ring coupling specimens and reinforced specimens with a combined coating. The supplementation of nanoparticle admixture to MAO coating reduces the friction factor between the cylinder sleeve face and the piston ring by 25-30%. The proposed technology can be used to reinforce work surfaces of new cylinder sleeves and recover worn out ones.

Improvement of manufacturing technology of cylinder sleeve bushings for marine diesel by centrifugal casting method

Improvement of manufacturing technology of cylinder sleeve bushings for marine diesel by centrifugal casting method

Effects of cylindrical pit array on tribological property of Piston–Cylinder sleeve friction pair in a BW-250 slime pump

This study designed a bio-inspired piston with a cylindrical pit array according to the BW-250 slime pump piston based on the surface structure of earthworm and leech. The friction was tested and analyzed. The friction pair mechanic system was modeled for finite element analysis, and the oil film test was supplemented. Results demonstrate that the bio-inspired piston show a lower friction force than the standard piston and a drag reduction rate that is above 10%. Cylindrical pit array can reduce the flow velocity of lubricating oil and increase the oil film pressure. The length and thickness of the oil film over the bio-inspired piston are higher than those of standard pistons.

Design features of engines of generation of A-41SI family

Design documentation on diesel engines of the A-41SI model is analysed. By results of the analysis it is revealed that on diesels of this type individual heads of cylinders, an electric starter with a pro-rate for start of engines are introduced, assembly units and details are improved: cranked shaft, sets of radical and shatunny inserts, cylinder sleeve, the piston, set of piston rings, casing with disks of the coupling of coupling, etc. Introduction of new constructive changes on A-41SI diesels allowed to raise their rabotosposbnost and durability.

Numerical minimisation of abrasive-dust wear in internal combustion engines

This paper presents a mathematical model to predict the abrasive wear of piston ring and cylinder sleeve in internal combustion engines due to dust particles. A parametric study is conducted on different group factors such as the abrasive action of the medium, engine design parameters, and engine physio-mechanical properties of the materials. The model reveals that it accurately predicts the effect of numerous factors on the wear process for the piston ring and cylinder sleeve. The model capabilities are demonstrated by the impact of air filtration efficiency on the engine component wear rate. It is found that dust particle size and concentration have significant effects on piston ring and cylinder sleeve wear rates. The numerical results show that the wear rate of both the piston ring and cylinder sleeve can be reduced by 80% when the air filter efficiency is increased from 97.8% to 99.4%.

An experimental study of the stress-strain state of the engine piston skirt on the engineless stand

The article describes the features developed by the authors of the profiling method of the piston skirt, provides the main parameters that affect the lubrication conditions of the piston skirt and the magnitude of mechanical losses. In computational studies, the basic formulas are given for determining the thickness of the oil layer in a piston skirt - cylinder sleeve conjunction to assess the nature of friction. To determine the deformations, the finite element method is used on the spatial model of the piston. To verify the finite element model, a stand for experimental studies was developed. The article describes the developed stand, the methodology and results of experimental studies of the stress-strain state of the two-piece piston skirt obtained at this stand and a comparative analysis of the results of the calculated and experimental studies of the stress-strain state of the two-piece piston skirt of a diesel engine. The research results showed that the developed stand can be used to verify mathematical models for calculating the stress-strain state of the piston skirt in the pilot production of internal combustion engine pistons to accelerate and reduce the cost of the piston design development process, as well as the results of experimental studies obtained at the stand, can be used as initial data for the developed mathematical model of the dynamics of the movement of the piston and the profiling of the piston skirt.

Friction and wear performance of bionic stripped piston of BW-160 slime pump

Bionic strips were designed and processed on the piston of BW-160 slime pump to improve its friction performance, decrease wear mass losses, and prolong service life. Nine stripped pistons were processed and manifested by different strip depths and included angles between stripes and piston surface. A workbench of slime pump piston was created to test the frictional force, oil film width, and wear mass losses. Test results demonstrated that the stripped structure can significantly decrease the frictional force on the piston. Optimal strip depth, included angle, and resistance reduction rates for stripped piston reached 2 mm, 90°, and 53.89%, respectively. The oil film on stripped piston was significantly wider compared with that of the standard piston, thus reducing frictional force between the piston and cylinder sleeve. The wear mass losses and the wear rate of the bionic piston are lower than that of the standard piston. Finally, the friction and stress of the piston are analyzed by finite element method, and the influencing mechanism on performance of pistons was discussed. The test results provide parameters for piston design of BW-160 slime pump for engineering.